Flame-resistive polyurethane foam composition

ABSTRACT

This invention relates to flame-resistive, nonflammable foam compositions comprising a flame-resistive organic foam material and an inorganic filler. The flame-resistive organic foam material is produced by using an aromatic polyisocyanate having no ortho substituent, an active hydrogen-containing compound, a foaming agent and a catalyst and the inorganic filler is graphite, talc, or inorganic fiber or the like. The flameresistive foam compositions are used as insulators for walls, chemical plants and tanks for storing a liquefied natural gas and other apparatus.

United States Patent 72 Inventor Kaneyoshi Ashida Tokyo, Japan [21]Appl. No. 736,571

[22] Filed June 13, 1968 [45] Patented Dec. 7, I97] [73] AssigneeNisshin Boseki Kabushiki Kaisha Tokyo, Japan [32] Priority June 15, 1967[3 3] Japan [54] FLAME RESISTIVE POLYURETHANE FOAM COMPOSITION 8 Claims,No Drawings [52] US. Cl ..260/2.5 AK, 260/2.5 AJ, 260/2.5 AW, 260/2.5AC, 260/2.5 AT, 260/77.5 NC, 260/77.5 AT

908,337 10/1962 Great Britain 260/2.5 AW X 4/1967 France 12/1967 FranceOTHER REFERENCES Condensed Chemical Dictionary, 5th Ed. Reinhold,(N.Y.), 1956, pages 286, 537, 728, and 1150* l 15 1. Call No. QDSCSDutch Patent Specification Publication No. 6705694 (1967), 15 pages.

Bulletin No. HR- 26 of E. l. du Pont de Nemours & Co., Inc., PublishedApr. 1958, pp. 11-12.

Saunders et al., polyurethanes, Part II, pp. 220- 225 (1964).

Primary Examiner- Donald E. Czaja Assistant E.raminerH. S. CockeramAttorneys-Robert E. Burns and Emmanuel J. Lobato ABSTRACT: Thisinvention relates to flame-resistive, nonflammable foam compositionscomprising a flame-resistive organic foam material and an inorganicfiller. The flame-resistive organic foam material is produced by usingan aromatic polyisocyanate having no ortho substituent, an activehydrogen-containing compound, a foaming agent and a catalyst and theinorganic filler is graphite, talc, or inorganic fiber or the like. Theflame-resistive foam compositions are used as insulators for walls,chemical plants and tanks for storing a liquefied natural gas and otherapparatus.

FLAME-RESISTIVE POLYURETHANE FOAM COMPOSITION This invention relates toa foam composition having outstanding flame resistivity, nonflammabilityand high thermalinsulating properties.

The first object of the present invention is to provide a foam havinghighly flame-resistive and nonflammable foamed material. The secondobject of the present invention is to provide a foam which generatesless smoke in a flame. The third object of the present invention is tooffer a foam having low thermal conductivity. Further objects of thepresent invention will be apparent in the following description.

Many lightweight materials or foamed materials consisting of inorganicpowder and plastics are well known. For example, it is well known thatinorganic-porous powder, e.g., perlite, is bonded with polyurethaneresin, phenolic resin and the like to make a lightweight andheat-resistive insulant. However, these insulants still have poor heatresistivity and high thermal conductivity. Highly flame-resistive, andlower thermally conductive foams have not yet been found.

In recent years, the demand of an insulator having the above-mentionedproperties have been increasing, because curtain wall core materials forhigh building, insulants for chemical plant, insulants for tanks forstoring a liquefied natural gas, etc., require highly flame-resistivefoams having lower thermal conductivity.

The foamed materials obtained by the present invention can satisfy therequirements mentioned above.

The main point of the present invention resides in the combination ofhighly flame-resistive organic foam material and inorganic filler.Precisely speaking, the present invention is explained as follows:

A flame-resistive foam composition is provided consisting of 5 to 200parts by weight of inorganic filler and 100 parts by weight offlame-resistive organic foam material, in which the inorganic filler isunoxidizable and nonhygroscopic, and is selected from the groupconsisting of powder, granule and fiber, the flame-resistive organicfoam material being composed of (a) an aromatic polyisocyanate having noortho substituent, (b) an active hydrogen-containing compound having amolecular weight of more than 300 and a functionality of at least two,(c) a foaming agent for the preparation of polyurethane foams, and (d) acatalyst selected from the conventional catalysts for trimerization ofsaid isocyanate group, the proportions of said components being such asto satisfy the relationship Ae/(Be-l-Ce+De) 2 and 0.4 Bw/Aw 0 whereinthe suffix e" represents the number of chemical equivalent of each ofthe components, suffix "w represents the weight of each of thecomponents, and said components Ce and De are eliminated from the aboveequation when components C and/or D are not reacted with the componentA.

An inorganic filler to be used in the present invention is unoxidizableand nonhygroscopic, and is selected from the group consisting of powder,granule, and fiber. If an inorganic filler which is oxidizable is used,the foam becomes flammable. If an inorganic filler which is hygroscopicis used, the foam absorbs moisture and the thermal conductivity of thefoam is increased. The state of the inorganic filler should be selectedfrom the group consisting of powder, granule, and fiber. The preferablefiller is powder or fiber and granular inorganic filler may be used.

Some examples of inorganic filler having a fire-extinguishing propertyare calcium carbonate, ammonium hydrogen phosphate, potassium iodide,potassium chloride, ammonium sulfate, barium sulfate, calcium sulfate.

Some examples of inorganic filler having no fire-extinguishing propertybut having the effect of reducing smoke density and increasing heatresistivity are graphite, kaolin, mica, talc, alumina, aluminum powder,asbestos powder, inorganic fibers such as glass fiber, rock wool andcarbon fiber, powders or granules of porous inorganic materials such asperlite, chips of foamed glass and pumice stone.

The amount of the inorganic filler is varied depending on the state,apparent density, particle size, etc. For example, the amount ofinorganic fiber to be mixed with liquid foaming ingredients by ordinarymeans is 10 to 15 percent, and in the case of spraying of both the fiberand the liquid foaming ingredients at the same time, the percentage maybe increased to more than 100 but less than 200 percent. In the case ofpowder, the percentage may increased up to 40 to 50 percent, and if thefoaming rate is slower, the percentage may be increased.

The method of mixing the inorganic filler and foaming ingredients isoptional. In a mixing method, the filler is added in one or moreingredients before foaming. In most cases, it is convenient that thefiller be added to the isocyanate component which is the largest part ofthe ingredients.

Another mixing method involves spraying of inorganic filler and foamingingredients at the same time. For this purpose, for example, a Petersonspraying machine for use in spraying of fiber-reinforced polyester, madeby Peterson Products Co., Ltd., may be used.

Preferable inorganic filler to be used in the present invention is onehaving a low specific gravity and lubricating property. The mostpreferable one is graphite powder, which produces a stable dispersionand does not produce sediment readily because of its low specificgravity. Talc powder is a preferable inorganic filler, which has alubricating property, and also gives higher flame resistivity to thefoam than that of graphite, but its dispersion is more unstable thangraphite.

The highly flame-resistive organic foam material can be made by the useof the following raw materials and specific reaction condition, whichare described in detail in copending US. Pat. application Ser. No.615,395.

Therefore, the patent is referred to herein as follows:

The polyisocyanates to be used in the present invention are aromaticpolyisocyanates having no ortho substituent. Some examples of aromaticpolyisocyanates are 4,4'diphenylm ethane diisocyanate, triphenylmethanetriisocyanate, biphenyl diisocyanate, m-phenylene diisocyanate,p-phenylene diisocyanate, 1,5-naphthylene diisocyanate and polymethylenepolyphenyl isocyanate or their mixtures.

A polyisocyanate having an orthosubstituent such as 2,4- and2,6-tolylene diisocyanate (isomer ratio /20), so called TDI, is not usedin the present invention.

The reason why the above-mentioned isocyanate is not preferable is thatthe orthosubstituent hinders the trimerization of isocyanate groups. Forexample, even if the aforementioned three elements are used in thepreparation of TD] based foam, the flame resistivity of the foamobtained is extremely poor.

The polyfunctional, active hydrogen-containing compounds to be used inthe present invention are polyhydroxyl and/or polycarboxyl compoundshaving a molecular weight of more than 300 and a functionality of atleast two.

The molecular weight of the active hydrogen compounds is more than 300.If the molecular weight is less than 300, the foam becomes more friable.For example, when glycerol or trimethylol propane-based foam is preparedby using the aforementioned combination of the three elements, the foamobtained is too friable for actual use.

The polyfunctional, active hydrogen compounds may be liquid or solid.The liquid state is preferable, but when it is solid, it may beliquefied by the addition of a solvent which is inert to an isocyanategroup. The active hydrogen-containing compound may be reacted withpolyisocyanate to form the liquid prepolymer. Nevertheless, if the soliddoes not dissolve in any inert solvent or does not form the liquidprepolymer, it cannot be used.

Some examples of the polyfunctional, active hydrogen compounds includepolyesters having polyhydroxyl and/or polycarboxyl groups, polyetherpolyols, polymerized fatty acids or so called dimer acids,hydroxyl-terminated polymers of copolymers of vinyl or diene compounds.

The polyfunctional, active hydrogen-containing compound can be usedalone or in combination.

Some examples of the preparation of the polyether polyol and polyesterare described in the book Polyurethanes, Chemistry and Technology by J.H. Saunders and K. C. Frisch, Part 1, pgs. 30-47, pgs. 349-351, and Part2, pgs. 857-865. Another example of a polyether polyol is described inJapanese Pat. No. 300,617, and vinyl copolymer is hydroxyl-terminatedcopolymer of butadiene and acrylonitrile. An example ofhydroxyl-terminated copolymer available in the market is Poly BD Resin(Registered trade name, Sinclair Co. Ltd.).

Polymerized fatty acid is also known as a raw material for thepreparation of polyurethane foams.

A preferable polyfunctional, active hydrogen compound is a polyetherpolyol having a molecular weight of more than 300 and a functionality ofat least two and more preferably the. polyether polyol is a triol ortetrol having a molecular weight of more than 300 and less than 1,500.

Foaming agents which are used for the preparation of conventionalpolyurethane foams may be used in the present invention. The foamingagents are nonreactive volatile organic solvents, compounds generating agas on heating and reactive foaming agents or their mixtures, asdescribed in the Saunders book, Part 1. Some examples of the nonreactiveorganic solvents are chlorofluoroalkanes, such asdichlorodifluoromethane, monofluorotrichloromethane,trichlorotrifluoroethane, n-pentane, n-hexane, 1,2- dichloroethane andtetrachloromethane. Examples of gasgenerating compounds arediazominobenzene, azodiisobutyronitrile and asohexahydrobenzonitrile.

Some examples of the reactive foaming agents include water,nitroalkanes, aldoximes, nitroureas, acid amides, boric acid, and acetylacetone.

Catalysts which are conventional forthe trimerization of isocyanategroups may be used in the present invention. Some examples are describedin the literature, such as Saunders, J. R. and Frisch, K. C.Polyurethanes, Chemistry and Technology," Part 1, pgs. 94-97, and 212,Beitchmann, B. D. Rubber Age, Feb. 1966, Beitchmann, B. D. I&EC- ProductResearch and Development, Vol. 5, No. 1, pgs. 35-41, Mar. 1966, andMicolas, L. and Gmitter, G. T., J. Cellular Plastics, Vol. 1, No. 1,pgs. 85-95 1965).

Examples of catalysts are (a) organic strong bases or salts thereof, (b)tertiary amine cocatalyst combinations, (c) Friedal Crafts Catalysts,(d) basic salts or organic weak acids, (e) alkali metal oxides, alkalimetal alcoholates, alkali metal phenolates, alkali metal hydroxides andalkali metal carbonates, (f) onium compounds from nitrogen, phosphorous,arsenic, antimony, sulfur and selenium, (g) epoxides and (h)monosubstituted monocarbamic esters. Preferred catalysts are those whichare soluble in other components of the formulation including forexample, polyether polyols and fluorocarbons.

Examples of organic strong bases are trialkyl phosphinestrialkyl-aminoalkyl phenols and 3-and/or 4-substituted pyridine.

Some examples of the tertiary amine-cocatalyst combinations aretriethylene diamine-propylene oxide, triethylenediamine-trioxymethylene, N,N,N,N'-tetramethyl 1,3-butanediamine-propylene oxide, pyridine-propylene oxide, N-methylmorpholine-propylene oxide, triethylene diamine-acetaldehyde,triethylene diamine-alkyleneimine.

Examples of Friedel Crafts catalysts include AlCl FeCl BF;,, and ZnClExamples of salts of organic weak acids includes (A) alkali metal saltsof monoor dicarboxylic acids of aliphatic, aromatic, alicyclic oraralkyl acids which are described in British Pat. No. 809,809 and also(B) alkali metal salts of organic weak acids excluding carboxylic acids,for example, salts of benzosulfmic acid, nitrophenols, picric acid,phthalimide, and diethyl phosphite.

Preferred salts for use in the present invention are alkali metal saltsof C -C carboxylic acids, especially potassium salts of such carboxylicacids, such as for example potassium octoate or 2-ethyl hexoate,potassium benzoate and potassium oleate.

Potassium salts are the most effective alkali metal salts. The activitydecreases in the order of potassium, sodium and lithium. Rubidium andcesium salts may also be used. Examples of common alkali metal oxidesare potassium oxide,. sodium oxide and lithium oxide. Examples of alkalialcoholates are sodium methoxide, potassium ethoxide, and potassiumalcoholates formed from ethylene glycol or a polyether polyol.

Examples of alkali phenolates are sodium phenolate, sodium2,4-dinitrophenolate, potassium 2 ,4,6-trinitrophenolate, sodium2,4,6-trichlorophenolate and potassium 2,4- dichlorophenolate.

Examples of alkali metal hydroxides and carbonates are hydroxides andcarbonates of lithium, sodium, potassium, rubidium, and cesiumrespectively.

Examples of onium compounds from nitrogen, phosphorous, arsenic,antimony, sulfur, and selenium are described in British Pat. No.837,120, for example, tetraethyl ammonium hydroxide,benzyltriethylammonium hydroxide, tetraethylphosphonium hydroxide.

Examples of epoxides are described in J. Cellular Plastics, Vol. I, No.1, pg. 85, 1965.

Examples of monosubstituted monocarbamic ester are described in BritishPat. No. 920,080.

The catalysts hereinbefore described are usually used in a state ofsolution or dispersion. Suitable solvents include water, dimethylformamide, dimethyl sulfoxide and similar solvents. Polyether polyol orpolyester may be also used as a solvent or a dispersion medium in thepresent invention.

Surfactants which may be used in the present invention are surfactantsfor the preparation of conventional polyurethane foam. Some examples area silicon surfactant and a nonionic surfactant. Some examples of thesurfactants are described in the Saunders book mentioned above.

The use of a surfactant is not always necessary in the presentinvention, and in some cases a foam having good cell structure isobtained without one. it is desirable however in almost all cases wherea fine cell structure is required that a surfactant should be used.

Flame retardants which may be used in the present invention are flameretardants for the preparation of conventional polyurethane foams.

Some examples are described in Saunders book mentioned above, e.g.,antimony oxide, halogen-containing phosphates, such as tris-chloroethylphosphate and tris-dibromopropyl phosphate, and halogen-containingorganic compounds, such as perchloropentacyclodecane,tetrachloronaphthalene, and phosphorus-containing polyesters or polyolsor halogen-containing polyetherpolyols or polyesters.

The use of a flame retardant is optional in the present invention.However the use of a flame-retardant, especially halogen-containingflame retardant is desirable to give the foam a short time ofafterflame.

A highly flame-resistant foam can be obtained by using the specified rawmaterials described above, and by using the specific conditionshereinafter described.

One of the specified conditions is the ratio between chemical equivalentof reactants that is, the equivalent ratio given by the formula: Ae/(Be-tCe-l-Del-Eei-Fe) must be more than 2.0, where A, B, C, D, E, and Frepresent polyisocyanate, active hydrogen-containing compound, foamingagent, catalysts, surfactant and flame retardant respectively, andsuffix e represents the number of chemical equivalent of the components.The formula is applied only to the components to be reacted with theisocyanate. When a component inert to the isocyanate is used, thecomponent must be omitted from the calculation of the equivalent ratiofrom the formula. Some examples of the inert components are flameretardants such as tris-chloroethyl phosphate.

The above-specified condition is a necessary one to give good flameresistivity to the foam by the formation of isocyanurate-rich structure,but the isocyanurate-rich structure alone is not a sufl'icient conditionfor obtaining the final product. Another necessary condition to give thefoam the flame resistivity is the weight ratio given by the formula: O.4Bw/Aw 0, where Aw and Bw represent the weight of the components A and Brespectively in formulation. If this weight ratio is more than 0.4 theflame resistivity of the foam that the foam obtained by the presentinvention is superior than perlite for the purpose hereinbeforedescribed. In addition, the foam obtained by the present invention canmake monolithic insulation, which is better than that made by usingdecreases markedly, even if the equivalent ratio is kept within 5 foamboard or any other boards. Furthermore, the speed of the statedlimitation. processing of pour in place is faster than that of board orpipe These two conditions are essential for the practice of the incoverinsulation. Besides, an advantage of the foam obtained vention. by thepresent invention is that less smoke is generated by the The foamcomposition obtained by the present invention thereof- E p rimental dataare shown below. has outstandingly high flame resistivity. An example ofcomto parative data is shown below.

light absorption Foam Maximum Residual Foam Burn through time 1 5(Bureau ofMines, RJ. 6366) A foam obtained by the present Min. inventionand containing graphite 23 0 ditto a tale 38 6 Urethane foam, nonbuminggrade 64 I0 Nonburning grade urethane foam by ASTM 1692-59T (containingl no filler) ditto (containing 30% ol'graphite) 8 The data were obtainedby using a method described in ditto (containing 3011 italc NFPAQuarterly Jan. [964, pp. 276-287. f zximz fgig22:22:? Conclusivelyspeaking, the foam obtained by the present indmowomainhg 40% 0mm 220 25vention has the following advantages; (a) outstandingly high flameresistivity, (b) very little smoke generation, (0) high thermalinsulation, as shown in the following example, (d)

The above-mentioned data shows unexpected flame renoncombusuble and (e)low denslty' sistivity of the foam obtained by the present invention.The EXAMPLE 1 other unexpected results are no explosive cracking andless shrinkage when the foam obtained by the present invention isSixty-four parts by weight of crude MDl (diphenylmethane exposed tofire. if the inorganic filler is not added in the foamdiisocyanate, 30-0t 31- P r Of functionality of ing ingredients, the foam obtained showsremarkable explo- 2.45) and 30 p rts by weight of graphite powder (lessthan sive cracking and shrinkage. The foam obtained by the present 35200 mesh) to make a dispersi n. A h r olution is invention issubstantially noncombustible. For example, a p p r d by mixing 12.5parts of a trimerization catalyst for an flame spread index of the foamby ASTM E-84 is about 10 to lsocyahale g p. p ts of sucrose-basedpolyether polyol l2. These data indicate large potential markets inbuilding inhavlng y y number of 460, Pa i of flame retardustry, chemicalplant insulation, aviation industry, mine indam (mschlomethyl P f P l Pof slllco" surfadam-L dustry, etc. 40 530 (trade name, Union CarbideCorp.) and 13 parts of Another example to indicate the Outstanding flresistivp trichloromonofluoromethane. The two solutions are mixed ty ofthe foam obtained by the present invention is as follows: together andsurfed make a foam- The foam was foamed in place in 80 mm. in thicknessout- The cure has a chem'cal eqlflvalem P U5 and the Side of an irontube having 200 mm diameter, 6 mm sucrose-based polyether has a chemicalequivalent of l22. thickness, 2,500 mm. length, a sheet of asbestoscloth was Thus the equvalem ratw'Ae/Bes wrapped outside of the foamedinsulant, a sheet of wire mesh 64 18 .5 14 was wrapped around it, and amortar coating was made over F5 122 the wire mesh. The insulated tubewas kept over a burner havand the weight ratio, Bw/Aw is I 8. 5l64=028lI ing 60 mm. of nozzle which was arranged cylindrically.

Pr as was burned at a rate of l 0 cubic meter er hour As anotherexperiment, 30 parts of talc powder is used ing t f th t be w easured ingems: stead of graphite in the above formulation. The physical proiempera e 0 e u as m perties of the foams obtained by the two experimentsare as follows:

A comparative experiment was made by using two layers of pipe cover ofperlite, 50 mm. in thickness. 30% mph: 30% 31C in the case of perliteinsulation, the temperature inside of Dusky (Rag/ms, 518 4 the tube inthe course of experiment was as follows: l30 C. Compressive strength,parallel after 10 min., 510 C. after 20 min., 640 C. after 30 min., '9'670 C ah r 35 min ditto, perpendicular to use 098 L07 e Burn throughtime, mm. I50 I80 On the other hand, in the case of a combination ofmortar 60 Water absorption, at 3.| 2.9 layer and the foam, thetemperature elevation was as follows: Thermal mnfuclivity 60 c. after 1hour, 310 c. after 10 hours, and the tempera- 'fj fjfjfif 2-3 2 3'" turewas constant at 3 10 C. for successive 24 hours. Dimensionai ,wbiiim w c01 01 If the temperature goes up above 700 C., the tensile parallel torise strength of iron decreases markedly. The above comparative 'f'Dimensional stability, -30 C.,

data indicate that the choice of insulant for fire protection isparallel m me very important in the case of some flameproof insulations,ditto, perpendicular to rise 0.7 tag, for the iron frame of skyscrapers,insulation of liquefied EXAMPLE 2 gas tanks, because poor insulantprovides many possibilities of great accidents. In other words, if poorinsulant is used in a Four kinds of foam were prepared according to thesame Skyscraper, the building Will o p y fife when the formulationdescribed in example i, except the variation of perature of iron framegoes up above 700 C. if a liquefi the amount of tale. The relation ofthe content of talc and natural gas tank equipped with poor insulant isin a fire, the burn through time wasasfollows: tank will explode whenthe temperature of tank goes up above Content of tale (1) 0 I0 20 30 40700 C. In such a case, it is unquestionable, based on the data,

EXAMPLE 3 This is an example of foams having markedly small afterflametime. Several kinds of foams were prepared by using the same formulationas in example 1. The amount of inorganic filler was kept at 7 percent.Measurement of afterflame time was as follows:

A hole, 50 mm. in diameter, was made in a sample having a size of 50l00xl00 mm. The hole was located over a bunsen burner head at a distanceof 35 mm., so that the flame may pass through the hole. The sample wasburnt for one minute, and the time which afterflame retains wasmeasured. Consequently, some effective compounds were found as follows:

Burn through time (min.) 50 I50 180 220 A inorganic filler afterflametime (see) no use 3 to (Nl-IQZHPO, 0.5 KCl l.0

Kl 1.0 5350, In (NH,)2S0, 1.0 NH,Cl l.5

Example 4 A foam was prepared according to the same formulation, as setforth in example 1 but using parts by weight of rock wool (10 to mm. inlength) instead of graphite powder. Glass fiber was well dispersed inthe foam, therefore, explosive cracking or shrinkage in fire were notobserved. The use of glass fiber instead of rock wool gave the sameresults.

What I claim is:

l. A flame-resistant foam composition consisting essentially of 5 to 200parts by weight of an inorganic filler and 100 parts by weight of aflame-resistant organic foam material, in which the inorganic filler is(i) resistant to oxidation, (ii) nonhygroscopic, and (iii) is selectedfrom a powder, granule, and fiber, and in which the flame-resistantorganic foam material is the reaction product of (A) an aromaticpolyisocyanate having only hydrogen atoms ortho to any NCO groups, (B) apolyfunctional active hydrogen-containing compound having a molecularweight greater than 300, (C) a foaming agent, and (D) a catalyst for thetrimerization of the NCO group, said (A), (B), (C), and (D) beingpresent in such amounts so as to satisfy the relationships:

(I) Ae/(Be+Ce+De) 2, and

(ll) 0.4 Bw/Aw 0 wherein e represents the chemical equivalent of eachcomponent, w represents the weight of each component, and Ce is equal tozero when component C does not react with an NCO group and De is equalto zero when component D does not react with an NCO group.

2. A foam composition according to claim 1, in which said foam materialalso includes (E) at least one surfactant, and (F) at least one flameretardant, and in which said (A, (B), (C), (D), (E), and (F) are presentin such amount so as to satisfy (l) Ae/(Be+Ce-l-De-l-Ee-l-Fe) 2 whereine represents the number of chemical equivalents of each of thecomponents, and Ce is equal to zero when component C does not react withan -NCO group, De is equal to zero when component D does not react withan -NCO group, Be is equal to zero when component E does not react withan NCO group, and Fe is equal to zero when component F does not reactwith an -NCO group;

3. A foam composition according to claim I wherein the equivalent ratiorepresented by relationship (I) is 3 to 10.

4. A foam composition according to claim 1, wherein said inorganicfiller is graphite powder.

5. A foam composition according to claim 1, wherein said inorganicfiller is talc powder.

6. A foam composition according to claim 1, wherein said inorganicfiller is inorganic fiber.

7. A foam composition as defined in claim 1 in which said foam materialalso includes (F; at least one flame-retardant and in WhlCh said (A),(B), (C (D), and (F) are present in such amount so as to satisfy (1)Ae/(Be+Ce+De+Fe) 2 wherein e represents the number of chemicalequivalents of each of the components and Ce is equal to zero whencomponent C does not react with an NCO group, De is equal to zero whencomponent D does not react with an -NCO group, and Fe is equal to zerowhen component F does not react with an NCO group.

8. A foam composition as defined in claim 1 in which the activehydrogen-containing compound is a sucrose-based polyether polyol.

2. A foam composition according to claim 1, in which said foam materialalso includes (E) at least one surfactant, and (F) at least one flameretardant, and in which said (A, (B), (C), (D), (E), and (F) are presentin such amount so as to satisfy (I) Ae/(Be+Ce+De+Ee+Fe)>2 wherein erepresents the number of chemical equivalents of each of the components,and Ce is equal to zero when component C does not react with an -NCOgroup, De is equal to zero when component D does not react with an -NCOgroup, Ee is equal to zero when component E does not react with an -NCOgroup, and Fe is equal to zero when component F does not react with an-NCO group.
 3. A foam composition according to claim 1 wherein theequivalent ratio represented by relationship (I) is 3 to
 10. 4. A foamcomposition according to claim 1, wherein said inorganic filler isgraphite powder.
 5. A foam composition according to claim 1, whereinsaid inorganic filler is talc powder.
 6. A foam composition according toclaim 1, wherein said inorganic filler is inorganic fiber.
 7. A foamcomposition as defined in claim 1 in which said foam material alsoincludes (F) at least one flame-retardant and in which said (A), (B),(C), (D), and (F) are present in such amount so as to satisfy (I)Ae/(Be+Ce+De+Fe)>2 wherein e represents the number of chemicalequivalents of each of the components and Ce is equal to zero whencomponent C does not react with an -NCO group, De is equal to zero whencomponent D does not react with an -NCO group, and Fe is equal to zerowhen component F does not react with an -NCO group.
 8. A foamcomposition as defined in claim 1 in which the activehydrogen-containing compound is a sucrose-based polyether polyol.